Zerlin



Feb. 21, 1956 H, ZERU 2,735,604

FIBER CONTAINER END STRUCTURE Filed June 18, 19515 FIBER CONTAINER END STRUCTURE Hans Zerlin, Dusseldorf, Germany, assignor of one-half to Jagenberg-Werke Akt.-Ges., Dusseldorf, Germany Application June 18, 1953, Serial No. 362,447 Claims. (Cl. 229-55) This invention relates to a container of fiber, paper, cardboard or the like carton-forming material used for packaging liquids such as beverages and has particular references to the construction of the closure-part in such fashion as to economically and simply produce a leakproof container.

Specifically the invention relates to a container of preferably square cross section which is made up from a flat rectangular blank, formed to a body sleeve by gluing, and closed by end pieces which are inserted into the sleeve and shaped to provide a tight and elfective seal in cooperation with the walls of the sleeve.

The sift and leak proofness of such containers depend not only upon the material used in their production but also and above all on the method of sealing the ends to the body sleeve. Conventional cartons are therefore provided with end pieces which, after having previously been creased and diecut, are formed to lids either before or during their insertion into the body sleeves. The closing edges of the end pieces form a right angle to the latter and they are sealed to the body sleeve by gripping, folding or beading operations under high pressure.

Additionally it has been proposed to insert flat end pieces into an open sleeve whose end has been provided with a crease or fold and with a view to obtain a tight closure, the components are compressed by suitable tools. Apart from the pre-preparation of the container parts by creasing or folding, such sealing methods require the use of complicated machinery and in addition the corner structures present particular difliculties in connection with obtaining tight seals.

It is therefore an object of the present invention to provide an inexpensive closure-part for the open ends of a body sleeve having flat upright walls. Both body sleeve openings may be sealed with such an end piece or only one of them, the other opening then being sealed by any conventional method.

It is another object of the invention to provide an inserted flat closure-part associated within the body sleeve in such a manner that the cut or peripheral edges of the flat end piece are pressed against the equally flat sleeve walls and closure-part being adhesively connected to the walls.

It is a further object of the invention to provide a closure part which is slightly larger in at least one direction than the distance between the inner faces of two opposite sleeve walls so that the closure part is, when inserted, slightly bent or flexed inwardly and thus continuously pressed against the inside of the other two opposite sleeve walls.

It is one more specific object that at least two of the opposed cut or peripheral edges of the flat closure part are slightly curved outwardly so as to bear against and flex the adjacent walls of the container sleeve, thereby assuring a tight connection between the peripheral edges of the end piece and the container walls.

Further and more specific objects of the invention will be apparent from the following description of the in nited States Patent C) vention taken in connection with the accompanying drawings in which Figure 1 is a perspective view illustrating a closed container embodying the invention,

Figure 2 is a plan view of the blank blank from which the body sleeve of the container is formed,

Figure 3 is a plan view of an end closure and diagrammatically illustrating the container walls associated therewith,

Figure 4 is an enlarged fragmentary elevational view of a corner of a container embodying the invention,

Figure 5 is a fragmentary perspective view of an upper corner of a container embodying the invention with parts removedto illustrate the glue seam, and

Figure 6 is a fragmentary longitudinal sectional view through the upper portion of a container embodying the invention.

The container illustrated in perspective in Figure 1 includes a body portion formed from the blank 1 which is shown in Figure 2. The blank includes panels 3, 4, 5 and 6 delineated by crease lines 2 and a glue flap 7 formed as a continuation of panel 3. When the blank is erected the panels 3 and 5 constitute the opposed longer side walls while panels 4 and 6 provide the opposite shorter side walls. When the blank is erected the glue flap 7 overlies and is adhesively secured to panel 6. Panel 6 has a pouring opening 8 provided therein, preferably by punching; this. opening is near the upper end of the panel and underlies a tear-off flap 9 formed in the adhesive flap 7 and delineated by a line of perforations 16. As shown, the outer portion of tear-0E flap 9 does not have adhesive thereon so that it can be grasped during a container opening operation.

The body sleeve 1, which is prismatic in the present instance, is closed by flat end pieces 11, one of which is shown in Figure 3. Each end piece is inserted into the open end of the sleeve so that the cut or peripheral edges 13 and 14 of the end piece 11 are pressed against the inner faces of the container walls 3, 4, 5 and 6. The end piece 11 is connected with the container walls by a peripheral fillet or glue seam 15 shown in Figures 5 and 6 and which seam is applied to the angle formed between the container walls and the outer surface of the end piece. The glue or adhesive used for forming seam 15 for sealing the end piece or inserted closure 11 to the container walls or panels 3, 4, 5 and 6 must be of a type which is elastic after setting to prevent the seam from breaking, it it is bent.

In order to provide a certain tension in the end piece 11 and to obtain a stronger pressure acting upon the walls 4 and 6, and to provide greater rigidity in the entire container, the distance between the two opposite edges 14 of the end piece 11 is slightly larger than the distance between the inner faces of the corresponding container walls 4 and 6. so that the end piece 11 is slightly flexed or bent towards the inside of the container, Figure 6.

In order to ensure that the other pair of opposed edges 13 of the end piece 11 exert suflicient pressure on the container walls 3 and 5, the edges 13 are as shown in Figure 3 curved outwardly, that is these edges are convex, whereby when the closure piece 11 is inserted into the container body the edges 13 deflect or bend panels 3 and 5 outwardly so that a close contacting engagement with the container walls 3 and 5 is definitely maintained. The close fit of all edges of the end piece 11 against all corresponding sides or panels of the container body is a prerequisite for maintaining a tight seal after application of the glue seam.

In the production of containers of the above kind, especially when they are intended for holding fluids or semi-fluids, it is the practice to provide the material from which the container is made, on one or two sides with a protective coating 16 of paratfin, plastic or the like. In this connection, at least the edges 13 and 14 of the closure must then also be provided with such a coating to prevent the fluid from leaking past the end piece 11. 1

Another prerequisite of a tight seal is, where applicable and as shown in Figure 4, the shaping of the corners of the end piece. Whenever the blank 1 as formed into a body sleeve has its crease lines 2 bulge inwards to wards the inside of the container then the corners of the end piece 11 are provided with a recess or notch 17 for accommodating the bulges so as to ensure that the end piece 11 fits snugly into the body sleeve and bears against the inner corners thereof.

It may further be advantageous to use a stronger material for the end piece 11 than for the body sleeve. This makes the container more rigid in cross section and facilitates the preferably mechanical inserting and sealing operations.

The above described sealing arrangement may be used for closing both ends of a body sleeve, or for closing only one end of a sleeve, the other end then being closed by any other desired arrangement.

What I claim is:

1. In a substantially rectangular fiber container, the combination of four interconnected side wall panels constituting a tubular body, and two inserted end closures each end closure including two pairs of opposed edges and prior to insertion each closure having a length between one of said pairs of opposed edges slightly greater than the distance between the inner faces of the corresponding container body panels, whereby upon insertion said closures are bowed toward the interior of the container, the other pair of opposed edges of said closures being curved outwardly whereby the contiguous wall panels are tensioned to assure a close fit of the closures in said container body.

2. The container of claim 1, including a peripheral fillet of elastic adhesive between said side wall panels and said inserted closures.

3. A fiber container comprising a body portion formed from a substantially rectangular blank folded into a substantially rectangular tube, a closure of sheet fiber inserted in each end of said tube, each closure having two opposite outwardly curved edges, and two opposed straight edges, the length of the curved closure edges and the length of the straight closure edges being so related to the distance between the respective inner faces of the tube that the straight edges of the closure lie on a straight line against twocontiguous opposite faces of the tube, the closures are bowed inwardly of the ends of the tube and the tube faces in contact with the curved edges are bowed outwardly and tensioned, whereby a close fit of all closure edges against all the tube faces is assured.

4. In a fiber container, a tubular body portion of substantially rectangular section including two pairs of opposed side wall panels, an inserted closure for at least one end of said tubular body portion, said closure comprising a fibrous sheet, substantially rectangular in plane and having a length along its major axis slightly longer than the distance between the opposed side wall panels of the body that are perpendicular to the major axis of the closure, said closure including opposed longer outwardly curved edges and opposed shorter straight edges, the two opposed body panels engaged with the curved edges of the closure being bowed outwardly by said edges and thereby tensioned, and the closure being bowed inwardly of the container body from the plane of the straight edges of the closure.

. 5. A fiber container as claimed in claim 4, in which the body portion has bulges extending inwardly toward the interior of the container at the corners thereof and said closure having recesses extending inwardly at its corners to accommodate the bulges and bear against the inner corners of the container.

References Cited in the file of this patent UNITED STATES PATENTS Harrison Nov. '4, 1941 i em... 

